DAS18A 750W Class D Amplifier Repair: This Did Not Totally Go To Plan!

I have three DAS18A Class D Amplifiers to repair. This did not go totally to plan, I should have realised because this is Learn Electronics Repair video number 666. Wanna find out what happened? You just gotta press PLAY
I work in collaboration with:
The Electronics Channel (live streams with Carlos and Detlef)
/ @theelectronicschannel
Gran Canaria Uncovered
/ @grancanariauncovered (with Detlef and Julie. Not electronics related)
Det Builds Stuff - / @detbuildsstuff (Detlef)
Retro Upgrade - / @retroupgrade (Carlos)
For All Your PCB needs: free $5 discount coupon
www.pcbway.com...
Equipment used in my videos. These are affiliate links, you pay the normal price and I make a small commission.
TEST METERS
ANENG AN8009 MULITIMETER
s.click.aliexp...
amzn.to/4da4Q7h
amzn.to/4fsjkkm
amzn.to/3yuf03q
amzn.to/4fwQOOD
www.banggood.c...
KAIWEETS HT118E MULTIMETER
s.click.aliexp...
amzn.to/3yC0ZRe
amzn.to/3SHIEcy
www.banggood.c...
VC480C+ MILLIOHM METER
s.click.aliexp...
amzn.to/46Gg1Cm
amzn.to/3YwUjyn
MESR-100 ESR METER
amzn.to/3yxQ0Zd
amzn.to/3WSr73A
s.click.aliexp...
XC6013L CAPACITOR METER
s.click.aliexp...
amzn.to/4cf2lzm
amzn.to/4dw9cp5
TM-902C TEMPERATURE METER
s.click.aliexp...
amzn.to/4fAz44L
amzn.to/4fBxD69
LCR-T4 COMPONENT ANALYZER
s.click.aliexp...
www.banggood.c...
amzn.to/3X4rOHv
amzn.to/3Agcj6h
FNB58 USB ANALYZER
s.click.aliexp...
amzn.to/3MgBFnn
amzn.to/4dyLU1H
www.banggood.c...
PCI POST ANALYZER
s.click.aliexp...
amzn.to/4dd8ihw
amzn.to/3LTpeO7
TL460S PLUS PCI_E ANALYZER
s.click.aliexp...
amzn.to/3WEsdi6
TOOLTOP ET120MC2 SCOPE
s.click.aliexp...
amzn.to/4dCaz5L
amzn.to/4dxOYLt
FNIRSI 1014D SCOPE
s.click.aliexp...
amzn.to/3AdZqK1
www.banggood.c...
NPS3010W 30V 10A PSU
s.click.aliexp...
amzn.to/4dzl2yM
T12 STATION WITH M8 9501 HANDLE
s.click.aliexp...
amzn.to/46E73W6
M8 9501 HANDLE
s.click.aliexp...
YIHUA 982 Soldering Station C210/C245
s.click.aliexp...
FNIRSI HS-02 PORTABLE SOLDERING C210/C245
s.click.aliexp...
amzn.to/3Yv7Ma5
QUICK 861DW
s.click.aliexp...
amzn.to/3WDF4B5
amzn.to/4ci7rdW
PROS'KIT SS-331H
s.click.aliexp...
INFIRAY P2 PRO IR CAMERA + MACRO LENS
s.click.aliexp...
www.banggood.c...
amzn.to/4coSRle
amzn.to/4coSV4s
TOOLTOP ET13S THERMAL CAMERA METER
s.click.aliexp...
ET13S MACRO LENS
s.click.aliexp...
OPTICAL MICROSCOPE
s.click.aliexp...
usa.banggood.c...
amzn.to/4dzBA9G
TOMLOV TM4K AF FLEX
amzn.to/3LY0YKs
tomlov.com/pro...
TL866 II+ PROGRAMMER
s.click.aliexp...
amzn.to/3SGKL05
CH341 PROGRAMMER
s.click.aliexp...
NC-559-ASM FLUX
s.click.aliexp...
DESOLDER BRAID (I use size 8045)
s.click.aliexp...
s.click.aliexp...
HX-T100 SOLDER (0.6MM)
s.click.aliexp...
ESD-11 TWEEZERS
s.click.aliexp...
Learn Electronics Repair is now on Discord! / discord
If you would like to support this channel
You can send donations
www.paypal.com...
You can subscribe to Patreon
/ learnelectronicsrepair
You can click Join to become a channel member
Thank you
Richard

[@LearnElectronicsRepair]

*Part two recorded and coming tomorrow* 😉

[@Hellhound604]

Hi Richard, just a big thumbs-up from me on your very methodical walkthrough on your style of fault-finding and diagnosis. For an old hand like me, I find your videos highly therapeutic, and every now and then I still learn new trick from you. As somebody that also educated beginners, I view your approach so calm and educational for a beginner, walking them step-by-step through your thought process…. Wish more of those electronics you-tubers would follow your process. Every decision you make is rational and well thought out. Ok, ok, there are sometimes that I would have followed a different approach, but hey, uor brains are different after all…. For example, I use an oscilloscope a lot more, even for measuring supply-rails. With modern scopes, you can measure voltage accurately enough and see potential problems (ripple, oscillations) with one measurement, but that is not a criticism, just showing a different approach. Showing people how to look at new thing, deduce how it works, drawing rough schematics to figure out how it SHOULD work, instead of just guessing blindly is a huge skill that beginners should get acquainted to, and I think you are an exemplary example of educating people how to do methodotical fault-finding.👍👍👍 BTW. I think you need to get some high-power 8-ohm resistors to test the amps with, instead of a speaker 😄

[@LearnElectronicsRepair]

Agreed, we all have different approaches, heck I even may take a different approach myself on any given day. Yeah I talk about dummy loads in part two, coming tomorrow

[@Nebbia_affaraccimiei]

36:20 some smoke on the right side there

[@Manticore1960]

Wow. You really have sharp eyes there! I had to watch it a couple of times before I saw it. When the unit is switched on for the second time without the current limit, there's a whisp of smoke that can be seen between the 2 video inserts on the right hand side.

[@pault6533]

That's where a couple TO-92's are. One of them was bent over at the time, was originally straight up and down.

[@LearnElectronicsRepair]

@@pault6533 All will be clear in part two which is now recorded ready for tomorrow 🙂

[@Dutch_off_grid_homesteading]

Heya, I have good eye side but had to look twice to see it well done 👍

[@user-yk8lf7ik1t]

I saw some smoke as well at around 36:00.

[@followthetrawler]

Smoke when you took it off the current limiter at 34:30 - just above the inset image of the bulb

[@dbriddie9525]

Jeez Richard, I think I jumped more than you!! LOL

[@MrMindlink]

...same here!!

[@MrPnew1]

33:55 Richard goes off camera to change his undies 😂 Make that one into an ElectoBoom style short Richard

[@lonndawg7554]

okay, let's continue with this repair... This type of amplifier that is mounted in the back of many brands of subwoofers,.... probably has similar techniques for diagnosing the problem, I would suspect that on average a common repair has to do with the output stages... From being overdriven but that's just speculation on me... But because this is a learning channel going through the process of diagnosing and explaining the circuitry is going to be a great learning experience and if we get the opportunity to repair all three who knows what we can learn.

[@Dutch_off_grid_homesteading]

Heya, I only saw the smoke after reading the comment and still had to look twice to see it. love to see these kinds of repair. curios how that repaired speaker is gone sound like. what time the upload will be plus/minus.

[@winlose3073]

Very interesting video Mr. Richard thanks!

[@garypoplin4599]

29:39 - Wow! I just learned a new English term - _Preexploded_

[@AnnaVannieuwenhuyse]

Class D amplifier repair is more important than ever!

[@weerobot]

Nice Jump Scare...

[@LittlePetieWheat]

Loving the suspense!

[@traditionaltools5080]

These plate amps are a pain and have floating grounds. Sometimes primary and secondary ground. Plus no discharge resistors. Also, I dont think that amp is class d. Those old style, linear power supply amps are pretty straight forward.

[@LearnElectronicsRepair]

Looks very much like a Class D to me

[@jonathanrose456]

❤

[@ToulKorkMan]

Can I send you my electronics to be repaired? It's a 2024 Lexus LM350H headunit.

[@GiC7]

Master